Water reservoir vessels or water storage tanks for storing water under pressure are known in the art. Examples of some reservoirs are disclosed in U.S. Pat. Nos. 6,532,758 5,707,518, 3,982,406, and 3,908,394. These water storage tanks have an inlet and an outlet and are generally in fluid communication with a valve or multiple valves, a water inlet and a filter. The tanks vary in shape and design in an attempt to maximize the volume of water they are able to store. A typical design may include the use of baffles, coils, loops and/or horizontally extending passages. A primary purpose of these tanks is to provide a reservoir where water can be stored in the refrigerator and kept at a cool temperature associated with the refrigerator, in preparation for subsequent use in an icemaker or dispersal through a water dispenser. To preserve the tank and prevent fatigue related failures, these tanks are typically operated under atmospheric conditions. This can cause unwanted dripping of water from the exterior dispenser. Similarly, dripping contributes to water waste and causes unsightly and unwanted water stains on and around the exterior dispenser. Additionally, water storage tanks operating at atmospheric pressure are typically disposed inline after the filtration member and valves because the filtration member requires a pressure above atmospheric pressure to operate properly. This permits filtered water, free of chlorine and other bacteria killing agents, to sit in the water tank, which may require the tank to be cleaned or flushed periodically to prevent bacterial growth within the tank.
An important aspect of water storage tanks is the amount of refrigerator space they occupy. Generally, considerations appurtenant to the water storage tank and keeping the filter cartridge accessible require the two to be positioned apart within the refrigerator. Inherently, such an approach necessarily requires the individual components to be piecemealed together thereby increasing the amount and length of water lines within the refrigerator. Invariably, the farther the tank is positioned away from the filter and points of disbursement (i.e., the icemaker and water dispenser), the longer water lines tubes and amount of line increases. Moreover, positioning the tank and filter apart may require two separate housings thereby occupying additional refrigerator space. Some considerations have been given to water storage tanks for storing water within the refrigerator while under pressure from the water supply line. U.S. Pat. App. No. 2004/0251210 uses a water storage means in fluid communication with the filter. However, little consideration is given to the failure criteria critical to the design of a tank for storing water under pressure and preserving the operational life cycle of the tank over the life the refrigerator.
While these tanks may have been useful for their intended purpose, there is a desire to provide a more compact pressurized water storage vessel having a high thermal stability, resistance to slow crack propagation and an overall resistance against fatigue related failures. Additionally, there is a desire to maximize the operational life of the vessel without losing the benefits and features desirable in water storage vessels within the refrigeration device, such as increased water retention volumes, decreased space requirements, placement flexibility, improved aesthetics and water quality, and simplified installation and integration into pre-existing and new designs/models.